Destabilization Pathways in Organometal Halide Perovskites

Organometal halide perovskites are the current focus of attention as a new class of materials for photovoltaic and photonic applications, with efficiencies already above 20%. Critical issues remain, primarily associated with their physico-chemical stability and their propensity to degrade over time. Building upon our works on these materials using TOSCA and parallel methodological developments on the instrument, this proposal seeks to obtain new and much-needed insights into their destabilization pathways and the role of hydrogen-bonding in driving these. To this end, we would need TOSCA and its new high-pressure capabilities to conduct experiments in the GPa domain on selectively deuterated specimens of methylammmonium lead iodide. These results will give us direct access to the local structure and vibrations immediately before structural collapse and amorphization.